The present invention relates to an optical pulse oscillator which is capable of simultaneously generating, in addition to the fundamental wave in the microwave band, higher harmonics ranging from millimetric to light waves and is suitable for use in constructing a light frequency measuring apparatus, for example. The invention also pertains to the light frequency measuring apparatus using the optical pulse oscillator.
If an electric signal of a frequency related to, for example, the frequency of laser light to be emitted from a laser light source is available from a laser driver, the frequency of light can be determined through utilization of the frequency of the electric signal, besides the frequency of light to be measured can be measured, based on the laser light. Moreover, if the frequency of laser light from the laser light source can be controlled electrically, it is of great utility in practice, because it permits the production of light of a desired frequency.
In view of the above, it is considered to obtain the frequency of a light wave by, for instance, frequency-multiplying microwaves from a microwave generator by use of a frequency multiplier. In this case, however, higher harmonics obtainable by the frequency multiplication of microwaves are limited to higher harmonics in the millimetric wave band at the highest and no higher harmonics corresponding to frequencies of light waves are obtainable. Thus, it is impossible, with the prior art, to obtain an electric signal of a frequency related to that of laser light and electrically control the frequency of laser light from the laser light source through mere frequency multiplication of microwaves.